Epidemiology of infantile hydrocephalus in Sweden. Reduced optimality in prepartum, partum and postpartum conditions. A case-control study.

The optimality concept developed by Prechtl was adopted to investigate a population-based series of infantile hydrocephalus (IH). The results were compared with those from a control series of newborns. The case series comprised 128 IH children born at term and 50 born preterm, and the control series 269 and 176, respectively. Cases with a prenatal cause of IH, as compared with those with a perinatal cause and controls, had significantly increased risk of IH by reduced optimality in the prepartum period. Peaks in the flow of non-optimal items in the prenatal group were repeated abortions or perinatal death in previous pregnancies, maternal disorder and twin birth. The profile of reduced optimality in term IH cases of undefined cause was similar to that of term cases with a prenatal cause. All IH cases had significantly increased reduced optimality in the postpartum period compared with controls. The increase was massive in cases where IH was of perinatal cause, with peaks in items of acidosis, apnea, respiratory treatment, infection and cerebral irritation. Reduced optimality in partum conditions did not discriminate between IH of pre- and perinatal cause. Reduced optimality in the prepartum, partum and postpartum periods in IH children, as compared with those with cerebral palsy syndromes, was nearly identical to that of hemiplegic, and significantly lower than that of diplegic and dyskinetic, cerebral palsy.